Red blood cell alloimmunization in 184 patients with myeloid neoplasms treated with azacitidine - A retrospective single center experience.

Alloimmunization to Red Blood Cell (RBC) antigens frequently occurs in patients with myeloid neoplasms (AML, MDS and CMML) and potentially poses the patient at risk for delayed hemolytic transfusion reactions and limited supply of compatible RBC-units. However, there is comparatively little data on transfusion associated characteristics in this patient cohort. We therefore retrospectively analyzed transfusion requirements and clinical outcomes of 184 patients with myloid neoplasms treated with azacitidine at the Paracelsus Medical University Salzburg, which were included in the Austrian Registry of Hypomethylating Agents. The mean blood component requirements for AML, MDS and CMML were 39.8, 67.4 and 31.4 RBC units and 31.7, 27.6 and 19.1 platelet (PLT) units respectively. In spite of an extended and stringent RBC unit matching policy (ABO, RhD, RhCcEe and K antigens), 20 (11%) patients formed at least one alloantibody ("allo-group"), whereas 164 patients (89%) did not ("non-allo-group"). The most frequent antibody specificity was anti-E, followed by anti-Wra -Lua, -D, -C and -Jka. Alloimmunization was associated with higher numbers of transfused RBC units (68 vs. 38; p=0.001), as well as with longer time under transfusion (16.7 vs. 9.4 months; p=0.014). Median overall survival (OS) did not differ significantly between the "allo"- and "non-allo-group".

T-cell death, phosphatidylserine exposure and reduced proliferation rate to validate extracorporeal photochemotherapy.

BACKGROUND AND OBJECTIVES: Extracorporeal photochemotherapy (ECP) is an established therapy in various diseases, such as cutaneous T-cell lymphoma and graft-versus-host disease. This study was performed to investigate the practicability of a flow cytometric T-cell evaluation after ECP as a tool to validate the quality of ECP procedures and to enable the comparability of treatments with different ECP devices. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMNCs) of healthy volunteer blood donors were treated by offline ECP. To quantify the effect of ECP on T cells in vitro, phosphatidylserine exposure and 7-aminoactinomycin D (7-AAD) reactivity as well as the proliferative activity of phytohaemagglutinin-induced, viable CD3(+) lymphocytes were analysed by flow cytometry. RESULTS: The expected T-cell death after ECP was confirmed by 7-AAD measurements. Phosphatidylserine exposure gradually increased between 20 and 70 h after ECP. Treatment-related inhibition of T-cell proliferation was 92.6 ± 1.4%. CONCLUSION: The combination of viability, phosphatidylserine exposure and T-cell division analyses by flow cytometry in a single-platform system provides a valuable tool to validate ECP procedures.

Bone marrow may be the preferable graft source in recipients homozygous for HLA-C group 2 ligands for inhibitory killer Ig-like receptors.

HLA class I molecules participate in natural killer cell regulation by acting as ligands for inhibitory killer cell Ig-like receptors (KIRs). One individual may express one or more inhibitory KIR lacking the corresponding HLA ligand. The role of this 'missing KIR ligand' constellation in hematopoietic SCT (HSCT) remains controversial and depends on incompletely defined transplant variables. We have retrospectively analyzed the effects of missing HLA-C group 1/2 and Bw4 KIR ligands in the recipients on the outcome in 382 HSCT, comparing 118 BMT to 264 PBSC transplants (PBSCT). In the multivariate Cox analysis of PBSCT, poor PFS was observed in homozygous HLA-C group 2 (C2/2) recipients (risk ratio (RR), 1.59; P=0.026). In contrast, C2 homozygosity was not unfavorable after BMT (RR, 0.68; P=0.16). C2 homozygous recipients (n=68) had better PFS after BMT than after PBSCT (RR, 0.17; P=0.001), due to fewer relapses (RR, 0.27; P=0.018). Missing Bw4 favorably influenced PFS after BMT (RR, 0.56; P=0.04), but not after PBSCT. These data suggest opposite effects of missing KIR ligands in BMT vs PBSCT. Larger studies are required to reassess whether BMT should be preferred to PBSCT as an option for C2/C2 recipients.

A novel HLA-A allele detected by sequence-based typing: A*68:66.

The novel allele HLA-A*68:66 differs from HLA-A*68:01: 01:01 by a synonymous single nucleotide exchange at position 102 (C→T) and three non-synonymous exchanges at position 257 (G→A), position 259 (A→G) and position 261 (C→G) in exon 2.

Fine mapping of T-cell immunoglobulin mucin domain gene 1 failed to detect a significant association with multiple sclerosis.

The T-cell immunoglobulin mucin (TIM) gene family encodes receptors on T-cells that regulate Th1- and Th2-cell-mediated immunity. Recently published data implied differential expression of human TIM molecules by mononuclear cells in cerebrospinal fluid of patients with multiple sclerosis (MS) and might therefore be involved in different phases of the pathogenesis of MS. The purpose of this study was to investigate the association of TIM1 gene polymorphism with susceptibility to and clinical progression in MS. In total, 272 patients with MS and 272 sex- and age-matched healthy blood donors from Western Austria were genotyped for 10 single nucleotide polymorphisms (SNPs). Five SNPs were located in the promoter region of TIM1 (rs7702920, rs41297577, rs41297579, rs9313422 and rs34333511). Another five SNPs were selected in exon 4 (rs1553316 and rs12522248) and in the intronic regions 4 and 7 of TIM1 (rs1553318, rs2279804 and rs2277025), respectively. None of these SNPs showed a significant association with MS after correction for multiple comparisons. Haplotype analysis of our data resulted in 11 haplotypes and showed no significant differences between MS patients and controls. Our findings suggest that even fine mapping of TIM1 shows no significant association of this gene with multiple sclerosis.

Up to 21-day banked red blood cells collected by apheresis and stored for 14 days after automated wash at different times of storage.

BACKGROUND AND OBJECTIVES: A closed-system technology (ACP-215, Haemonetics, Braintree, MA) enables automated washing and extended storage of frozen red blood cells (RBC). This technology was applied to wash banked RBC for removal of undesirable protein and metabolites before transfusion. We studied protein and metabolite depletion as well as RBC metabolism and viability up to 14 days postwash with regard to various pre-storage times. MATERIALS AND METHODS: Thirty RBC units were collected by means of apheresis and subdivided into three arms based on prewash storage time period (6 days/group 1, 14 days/group 2, 21 days/group 3). Wash efficacy (protein depletion, IgA), RBC metabolism (pH, lactate, potassium, haemolysis) and cell viability (ATP) were analysed immediately and 14 days after washing. RESULTS: Total protein and IgA postwash were lowered by automated wash in all groups and uniformly met EC guidelines. Potassium (mmol/l) was below 1.2 mmol/l postwash and significantly below prewash values in all groups, even after 14 days of storage (prewash vs. postwash; P < 0.05). RBCs washed after 14 and 21 days, respectively, showed significantly lower pH values and lower ATP content than RBCs washed after only 6 days of storage. Haemolysis rate remained significantly below 0.8%, the maximum level recommended by the EC guidelines, immediately and 14 days after washing in all units. CONCLUSION: Our data confirm that RBC units banked up to 21 days can be effectively protein- and potassium-depleted with the ACP-215 independent from prewash storage time. With respect to high ATP levels and pH, postwash storage of 2 weeks should be limited to units not older than 7 days before wash. This new washing technology ensures better standardization in washed RBC and provides blood centres with a logistical alternative to 24-h washed RBC products.